dekas

Deka- is a Greek-derived decimal prefix meaning ten. In English and in the International System of Units, the standard form is deka- with the symbol da-. When used, it forms names like dekameter (decameter) or dekaliter. The plural dekas is not used in official SI usage; some texts may use "dekas" to refer to multiple tenfold multiples in informal contexts, but this is nonstandard.

Beyond technical usage, dekas may appear as a surname in Greek-speaking communities and among diaspora populations. In such cases, it is unrelated to the SI prefix and is simply a family name.

In other domains, "dekas" may appear as a place name, brand, or fictional term, depending on authorial choice. The lack of a single, widely recognized definition means interpretation relies on context.